Stanislaus Pascal Franchot Tone was born in Niagara Falls, New York, the youngest son of Dr. Frank Jerome Tone, the wealthy president of the Carborundum Company, and his socially prominent wife, Gertrude Van Vrancken Franchot. His maternal great-grandfather was congressman Richard Franchot. Tone was also a distant relative of Wolfe Tone (the "father of Irish Republicanism"); his fourth great-grandfather John Tone was a first cousin of Peter Tone, the father of Wolfe Tone.[1] Tone was of French Canadian, Irish, and English ancestry. Through his ancestor, the nobleman Gilbert BasqueHomme (Bascom), he was of French Basque descent.[citation needed]

Tone was in The Belt (1927), Centuries (1927–28), The International (1928), and a popular adaptation of The Age of Innocence (1928–29) with Katherine Cornell. He followed it with appearances in Uncle Vanya (1929), Cross Roads (1929), Red Rust (1929–30), Hotel Universe (1930), Pagan Lady (1930–31).

These were intense and productive years for him; among the productions of the Group he acted in were 1931 (1931), Maxwell Anderson's Night Over Taos (1931), The House of Connelly (1931) and John Howard Lawson's Success Story (1932) directed by Lee Strasberg. Outside the Group he was in A Thousand Summers (1932).

Tone was the first of the Group to go to Hollywood when MGM offered him a film contract. In his memoir on the Group Theater, The Fervent Years, Harold Clurman recalls Tone being the most confrontational and egocentric of the group in the beginning. Nevertheless, he always considered cinema far inferior to the theater and recalled his stage years with longing. He later provided financial support to the Group Theater, which often needed it. He returned to stage work sporadically after the 1940s.

Tone took their split hard, and his recollections of her were cynical — "She's like that old joke about Philadelphia: first prize, four years with Joan; second prize, eight". However, many years later, when Tone was dying of lung cancer, Joan often cared for him, paying for his food and medical treatments. At one point during this period, Tone suggested they remarry. Crawford refused.

In 1951, Tone's relationship with actress Barbara Payton made headlines when he was rendered unconscious for 18 hours and sustained numerous facial injuries following a fistfight with actor Tom Neal, a rival for Payton's attention. Plastic surgery nearly fully restored his broken nose and cheek. Tone subsequently married Payton, but divorced her in 1952 after obtaining photographic evidence she had continued her relationship with Neal.[12]

In 1956, Tone married Dolores Dorn, with whom he appeared in a film version of Uncle Vanya (1957) which Tone directed and produced. The couple divorced in 1959.